Synergistic inhibition of pneumococcal growth by Dolosigranulum pigrum and Corynebacterium pseudodiphtheriticum: insights into nasopharyngeal microbial interactions.
Streptococcus pneumoniae is a nasopharynx colonizer that can invade sterile tissues, causing invasive pneumococcal disease (IPD). Dolosigranulum pigrum and Corynebacterium pseudodiphtheriticum are commensal bacteria commonly isolated from the nasopharynx of healthy children, potentially playing a pr...
| Autores: | , , , , , , , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2025 |
| País: | España |
| Institución: | Fundació Sant Joan de Déu |
| Repositorio: | r-FSJD. Repositorio Institucional de Producción Científica de la Fundació Sant Joan de Déu |
| OAI Identifier: | oai:fsjd.fundanetsuite.com:p28655 |
| Acceso en línea: | https://fsjd.fundanetsuite.com/Publicaciones/ProdCientif/PublicacionFrw.aspx?id=28655 |
| Access Level: | acceso abierto |
| Palabra clave: | Corynebacterium pseudodiphtheriticum Dolosigranulum pigrum Streptococcus pneumoniae capsular serotype invasive pneumococcal disease nasopharyngeal microbiota |
| Sumario: | Streptococcus pneumoniae is a nasopharynx colonizer that can invade sterile tissues, causing invasive pneumococcal disease (IPD). Dolosigranulum pigrum and Corynebacterium pseudodiphtheriticum are commensal bacteria commonly isolated from the nasopharynx of healthy children, potentially playing a protective role. This study aims to analyze the effects of D. pigrum and C. pseudodiphtheriticum on S. pneumoniae in vitro growth. Pneumococcal strains were collected from IPD patients and healthy carriers in Catalonia (2016-2023). D. pigrum and C. pseudodiphtheriticum strains were isolated from a healthy child's nasopharynx. S. pneumoniae was co-cultured with each commensal bacterium in triplicate experiments. Pneumococcal growth was quantified using a real-time PCR assay targeting the lytA gene. The effect of commensal bacteria on pneumococcal growth was evaluated using a linear mixed-effect regression model. Twenty-eight pneumococcal strains expressing 24 different serotypes and 27 clonal types were analyzed (18 isolated in blood and 10 in nasopharyngeal aspirate). Pneumococcal growth was decreased by D. pigrum (ß = -0.763, 95% confidence interval [CI]: -0.94 to -0.59, P < 0.0001) and C. pseudodiphtheriticum (ß = -0.583, 95% CI: -0.76 to -0.41, P < 0.0001). The combined presence of both had a stronger inhibitory effect (ß = -0.971, 95% CI: -1.15 to -0.79, P < 0.0001). No association was found between isolation site or serotype with pneumococcal growth. D. pigrum and C. pseudodiphtheriticum significantly reduced pneumococcal growth, with a synergistic effect when combined. This antagonistic effect supports the potential protective factor of healthy nasopharyngeal microbiota against IPD and the development of these microorganisms as probiotics.IMPORTANCEInvasive pneumococcal disease (IPD) is a significant worldwide health challenge. The present study highlights the significant inhibitory effect of two commensal bacteria, Dolosigranulum pigrum and Corynebacterium pseudodiphtheriticum, on pneumococcal growth, with a stronger effect observed when both bacteria are present together. Through testing different strains of S. pneumoniae and the implementation of a robust statistical model, this research advances in the knowledge of microbial ecology and provides evidence to support the development of the use of these commensal bacteria as probiotics. These results emphasize the possibility of using the nasopharyngeal microbiota's natural interactions to mitigate the risk of IPD. |
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